July 2002 product reviews

flected power and SWR simultaneously.
stances you’ll be concerned with average
test gear you’ll ever own is your watt-
power, leaving it up to you to “ask” for
do an adequate job in this department.
the output of your transceiver and adjust
a calibration knob. Other wattmeters dis-
at 2, 14, 28, 50 and, for those meters with
it accordingly. A wattmeter can alert you
play only forward or reflected power—
curacy tests were conducted at 5, 100 and
power at a particular point. With the for-
reading. That is, they can display power
levels that are present at extremely brief
wattmeter to calculate feed line loss—just
SSB signal that can have a relatively low
compare the power at the input of the feed
average power, but include numerous
bursts of higher peak power that exist for
are not laboratory-grade meters. Al-
ers include wattmeters, but these are tied
meters: active and passive. The active
brated ARRL Lab equipment, it isn’t fair
stalled. In contrast, a stand-alone wattme-
wattmeters sample peak power levels elec-
to expect the same level of performance.
If you require extreme accuracy, you have
nient when you’re trying to troubleshoot
take a measurement at the feedpoint of an
can tolerate reasonable accuracy; you
guess, active wattmeters provide the most
don’t need to split hairs at tiny fractions
accurate peak-power readings. In most in-
DIAMOND SX-200DIAMOND SX-200
stacked scales and a single meter movement
lighted, but you have to supply an external12-V power source (Diamond includes the
200 you have to use the front-panel switches
to jump between forward power, reflectedpower and SWR functions as necessary. The
SX-200 is a passive peak-reading meter with
a switch to select either average or peak-
power modes. To measure SWR, you mustfirst calibrate the SX-200 in the calibrate
control, then switch to the SWR mode. TheSX-200 specifies a frequency range of 1.8
desktop meter, the SX-200 measures 6 × 2
one of the heftier meters of the bunch.
quite good in our Lab tests, but the for-ward power accuracy could have beenbetter. From a user standpoint, we foundthe need to frequently change switch set-tings a little cumbersome. The meter isruggedly built, however, with a sleek, at-tractive appearance.Manufacturer: Diamond Antenna, 435
tel 760-744-0900; www.rfparts.com/diamond/. $99.95.DIAMOND SX-20C
button selects average or peak power dis-
× 35/16 × 33/4 inches) designed to be as gedly built as the Diamond SX-200. In plays. The frequency range of the“hands off” as possible. The SX-20C is
intended for mobile use, but it works just
housed in a 41/2 × 31/4 × 31/4-inch alumi-
Manufacturer: Diamond Antenna, 435
num case. The display is illuminated and,
other (the so-called “cross needle meter”
92069; tel 760-744-0900; www.rfparts.com/diamond/. $89.95.
12-V dc “wall wart” supply to power the
PALSTAR WM150DIAMOND SX-20C
Frequency Range: 3.5-150 MHzPower Range(s): 30/300 WPEP Measurement: None
Actual Forward Power (Average only)Frequency (MHz)From July 2002 QST ARRLPALSTAR WM150
Palstar states that the meter is not specifi-
Frequency Range: 1.8-150 MHzPower Range(s): 300/3000 W
cally designed for accuracy above 50 MHz.
45356; 937-773-6255; www.palstarinc.com/. $89.95.DAIWA CN-101L
the cross-needle meter design more than20 years ago, and it has been showing up
101L is a desktop meter with three switch
selectable power levels: 15, 150 and 1500W. The frequency range is 1.8 to 150
was 1.7:1 (2.5:1 indicated onmeter), possibly affecting
unit requires more than 5 Wfor proper operation.
requiring external power isused. “Passive” indicates a
peak envelope power (PEP). The CN-101L isn’t well designed for peak powermeasurement, and the manual says asmuch (see the note in the data table).
pany, 60 9th Floor, TOC Building, 22-17-7 chome, Nishi-Gotanda Shinagawa-ku,Tokyo, Japan. Available from several US
DAIWA CN-101L
dealers. Typical street price $94.75.DAIWA CN-410M
Power Range(s): 15/150/1500 WPEP Measurement: Passive†
that also features Daiwa’s famous cross-
pleasant experience in the shack as well.The CN-410M is designed for operation
(peak or average). The CN-410M comeswith a mobile mounting bracket. Accord-
3 W, but this aspect of its performancewas not tested.
CN-410M has been discontinued. How-ever, this meter is still quite popular at
hamfest fleamarkets and on-line auctions.
*According to the CN-101L manual, “For monitoring PEP, a condensor is placed into
detector circuit. This function can not hold peak envelope power.”
but we noticed that its accuracy declined at
†For PEP monitoring, “Active” indicates that a circuit requiring external power is used.
the high end of its range. Also, on 2 meters,
“Passive” indicates a circuit that requires only RF.
‡Amplifiers for 6 meters or 2 meters were not available at the time of testing.
a significant figure at this frequency.From July 2002 QST ARRLMFJ ENTERPRISES MFJ-860
Frequency Range: 1.8-54 MHzPower Range(s): 30/300 WPEP Measurement: None
Actual Forward Power (Average/Peak)Frequency (MHz)DAIWA CN-410M
Actual Forward Power (Average only)Frequency (MHz)Note*SWR on input was 2:1 at 100 W on 144 MHz, so test was not
dealers. Typical street price $98.75.
and at 5 × 31/2 × 5 inches it is the largest
VECTRONICS PM-30
meter tested for this review. A Lexan face
varied considerably according to thepower level and frequency. SWR accu-racy was fair.Manufacturer: Vectronics, 300 Indus-
trial Park Rd, Starkville, MS 39759;800-363-2922; www.vectronics.com/.VECTRONICS PM-30
Frequency Range: 1.8-60 MHzPower Range(s): 300/3000 W
MFJ ENTERPRISES MFJ-860
wattmeter in this group. At about 41/2 ×
31/2 × 21/2 inches, it is also among the
smallest. It sports the convenient cross-
readings. In fact, the only switch on the
two power ranges: 30 and 300 W. TheMFJ-860 is average-reading only. The
was surprisingly accurate. Its insertionloss was also acceptable and well within
related to the small size of the meter dis-play itself. It can be difficult to read un-
†For PEP monitoring, “Active” indicates that a circuit requiring external power is used.
“Passive” indicates a circuit that requires only RF.
‡Amplifiers for 6 meters or 2 meters were not available at the time of testing.
674-1800; www.mfjenterprises.com/.$44.95.From July 2002 QST ARRL

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